ML20247B639
| ML20247B639 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/31/1997 |
| From: | NORTHEAST NUCLEAR ENERGY CO. |
| To: | |
| Shared Package | |
| ML20247B635 | List: |
| References | |
| NUDOCS 9805080125 | |
| Download: ML20247B639 (18) | |
Text
_
Annual Environmental Protection Plan Operating Report January 1 - December 31,1997
\\
Millstone Unit 3 Environmental Protection Plan prepared by Northeast Utilities Service Company P.O. Box 270 11artford, Connecticut 06141-0270 April 1998 9805000125 900430 PDR ADOCK 05000423 PDR R
f i
I i
l l
Annual Environmental Protection Plan Operating Report - 1997 1.
Introduction This report covers the period January 1 - December 31,1997. Unit 3 was placed on the NRC Watch List on January 29,1996 and has been off-line since March 30,1996, following the declared inoperability of the auxiliary feedwater containment isolation valves. Since then, Unit 3 has been working to verify corrective actions and to demonstrate readiness for startup. Unit 3 was shut down during the entire report period.
i As required by the Millstone Unit 3 Environmental Protection Plan, this Annual Environmental Protection Plan Operating Report (AEPPOR) includes:
1) summaries an i analyses of the results of environmental protection activities, 2) a list of EPP noncompliance, 3) a list of all changes in station design or operation which involved a potentially significant unreviewed environmental question, and 4) a list of non-routine reports, describing events that could result in significant environmental impact.
i 2.
Environmental Protection Activities i
2.1 Annual National Pollutant Discharge Elimination System (NPDES) Report of Ecological Monitoring (EPP Section 4.2)
Paragraph 5 of the referenced NPDES permit requires continuation of biological studies of Millstone Nuclear Power Station (MNPS) supplying and receiving waters, entrainment studies, and intake impingement monitoring. These studies include analyses ofintertidal and subtidal benthic communities, finfish communities, entrained phmkton, lobster populations, and winter flounder populations. Paragraph 13 of the permit requires an a.mual report of these studies to the Commissioner of Er Jonmental Protection.
The report that fulfills these requirements for 1997, Monitoring the Marine Environment of Long Island Sound at Millstone Nuclear Power Station. Waterford. Connecticut - Annual Renort.1997, presents results from studies performed during 3-unit operation, and compares them to those from 2-unit operation.
Past reports have indicated that the added cooling water flow for Unit 3 affects impingement and entrainment, causes sediment scouring near the MNPS discharges, and alters the characteristics of thermal ellluent plume. The extended shutdown of MNPS since 1996 has also caused some changes to the physical environment in the vicinity of the station discharge.
The biological effects of these changes are summrized in the Executive Summary section of the above-named report (Attachment
- 1) and further discussed in the report itself(Attachment 2).
1 i
)
1997 AEPPOR 1
I
{
1
2.2 Efiluent Water Quality Monitoring Paragraph 6 of the referenced NPDES permit requires monitoring and recording of many water quality parameters at MNPS intakes and at 37 monitoring points within the plant, including outfalls of each unit to the effluent quarry, and outfall of the quarry to Long Island Sound. Paragraph 11 of the permit requires a monthly report of this monitoring to the Commissioner of the Connecticut Department of Environmental Protection (DEP). The report that fulfills these requirements, Monthly Discharge Monitoring Renort (DMR), includes data from all three Millstone units. Those items that pertain to Unit 3 are summarized in Table 1.
During 1997, several NPDES pemiit exceedances (i.e., events where the value of a parameter was beyond the permitted limit) or exceptions (i.e., events where a permit condition was not met) were reported for discharges associated with Unit 3. We also included in the listing below other environmentally-related events which did not necessarily involve NPDES permit exceedances or exceptions, but had been reported m l
Millstone DMRs for informational purposes.
During 1997, wastewaters containing small amounts of hydrazine were detected in the Ilign Level Waste Drain Tanks at DSN 001C-2 and the Low Level Waste Drain Tanks at DSN 001C-3. Protocols were established with the DEP regarding the processing and reporting of the presence of hydrazine in these wastewaters.
Consistent with these protocols, these wastewaters were processed to remove hydrazine to below detectable limits based on spectrophotometry (<5 ppb).
Beginning in August 1997, based on correspondence from the DEP, Millstone was no longer required to process or notify DEP of the presence of hydrazine at levels below 350 ppb at certain Unit 3 discharges.
In January, a weekly grab sample from DSN 001C-2 (Radiation Waste Test Tank e
Discharge) was inadvertently not analyzed for lithium.
in Janutry, the inline pil monitor was out of service at DSN 001C (Unit 3 e
Discharge). Grab samples were taken every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> in lieu of continuous monitoring, with results submitted with the January 1997 DMR. This uoes not represent a permit exception.
A January weekly sample at DSN 006 (Unit No. 2 and Unit No. 3 Non-contaminated Floor Drains including Boric Acid from Steam Generator Treatment, Continuous Blowdown from R.O. Treatment of Makeup Water, Unit No. 2 and Unit No. 3 Diesel Generator Cooling Water Discharge, Water Softener Regeneration Drainage, Unit No. 3 Control Building Cooling System Drainage, Water Washes, Clean Water Drains, and Surface Water Runoff), taken during a heavy rain event, had a Total Suspended Solids (TSS) value of 57.4 ppm 1997 AEPPOR 2
l l
(NPDES permit limit 30.0 ppm). As the permit prescribes sampling during dry weather flows, TSS was subsequently resampled during a dry period, revealing a TSS concentration of 10.3 ppm. This initial value is not believed to be a permit exceedance, as sample conditions were not representative of permit requirements.
in January, qt rterly toxicity testing at DSN 001C revealed an 88% survival rate e
for Mysidopsis bahia (mysid shrimp), whereas a 90% survival rate is required. A resample was taken which passed, with a 94% survival rate. Concurrent testing with Cyprinochm variegatus (sheepshead minnow) showed 100% survival. This j
does not constitute a permit exceedance, as the limit would have been exceeded
)
only if two consecutive tests, or three tests within a year, had failed.
1 1
Between January 26 and February 12,1997, hydrazine was released through DSN e
001C-5 (Aux Ileat Exchanger (Service Water) Discharge) due to a tube leak in a heat exchanger in the Reactor Plant Closed Cooling Water (RPCCW) system. On February 12, the source of the leak was traced to the 'A' heat exchanger, which was then taken out of service, pending repair.
While the estimated hydrazine concentration in the discharge,0.23 ppb, was calculated to be below the limit of detection, the NPDES permit does not authorize release of hydrazine from this discharge point.
l In February, a worker noticed what appeared to be soapy water in a Unit 3 Turbine Building floor drain which discharges to DSN 006. DSN 006 was sampled for the presence of soapy water and none was found. It is therefore inconclusive how much, if any, of this solution was actually discharged.
t in March, approximately 300 gallons of wastewater were drained from the Unit 3 j
e Reactor Plant Chilled Water System and discharged via DSN 001C-9 (Non-j Contaminated Closed Cooling Water System Drainage Discharge), as authorized.
l Subsequently, NNECO became aware that this discharge may have contained small amounts of dichlorodifluoromethane (R-12), a refrigerant; laboratory results revealed the presence of R-12 in the A and B loops of the Reactor Plant Closed Cooling Water System at 44.8 ppb and 60.7 ppb, respectidy, and in the Reactor Plant Chilled Water system at 98.5 ppb. Between April and July, Millstone voluntarily sampled the Unit 3 Closed Cooling Water System discharges at DSN 001C-2 and 001C-3. While R-12 was not found above detection limits in any subsequent sampling, trace levels of other organic substances were detected. As to these substances, their presence is believed to result from the byproducts of solvent usage in the plant. It is also possible that l
sample contamination during laWratory testing may be a cause for some of these values. NNECO, based on its review of all sampling results and after discussions with the DEP, discontinued its voluntary sampling program on July 9,1997.
1997 AEPPOR 3
l l
l l
t i
In March, while a biennial valve position stroke test of the service water dilution flow valve was being performed, the valve was inadvertently left closed for 8 minutes and 32 seconds.
As a result, no service water dilution of the hypochlorite flow occurred.
It was estimated that the hypochlorite pump injection rate at this time was 2.5 gallons per hour. Due to the number of variables affecting this system such as water temperature, chlorine demand,
)
dilution flows, etc., the concentration of residual chlorine that would have been discharged to the service water system cannot be calculated. Thus, it cannot be determined if an actual exceedance of the limit for residual chlorine occurred.
In h1 arch, routine analysis of a Unit 3 "A" Auxiliary Boiler sample showed 92 ppm hydrazine. The permitted limit for hydrazine in this discharge (DSN 001C-6(b)) is 75 ppm. On the following day, when the discharge was again sampled, hydrazine was back within pennitted limits at 35 ppm.
On April 28, approximately two gallons of No. 4 Fuel Oil spilled onto pavement at Unit 3. Nevertheless, this was reported to the National Response Center, the DEP and the U.S. Coast Guard.
Commencing in May 1997, Millstone began to voluntarily sample discharges from the Unit 3 auxiliary boiler room oil and water separator for oil and grease on a periodic basis. The oil and water separator discharges to DSN 001C-6(b) and Millstone's NPDES permit does not address the discharge of oil and grease from this location. For May 1997 through December 1997, Millstone reported 5 sampling results with levels of oil and grease above the limit of detection.
On May 4, chlorinated service water was released to Long Island Sound via the Unit 3 sluiceway (DSN 004). The water was released at approximately 10 gallons per minute and contained 0.06 ppm free available chlorine (FAC) and 0.08 ppm total residual chlorine. DSN 004 is authorized to discharge screen wash wastewater from Unit 3. It was determined that the source of chlorinated service water in the sluiceway was a leaking service water isolation valve in the cross-connection line between the service water and screen wash systems, which was subsequently repaired. While chlorine concentrations in the sluiceway were well below those permitted for other discharges (e.g. 0.25 ppm FAC at DSN 001C-5), the NPDES permit does not address the discharge of chlorine from this discharge point.
On May 14, approximately 320 gallons of wastewater were discharged from DSN 001C-6(b) with a hydrazine concentration of I88.7 ppm (permit limit 75 ppm).
In May, NNECO advised the Department of the discharge of service water system strainer backwash water containing chlorine at Unit 3.
As part of 1997 AEPPOR 4
i
~
NNECO's response to this matter, Unit 3 developed procedures which manually halt the injection of chlorine into the service water prior to backwash of the service water strainers, thereby allowing the backwash water to be free of chlorine. Normal chlorination of the service water is then resumed following strainer backwash. On August i1,1997, NNECO notified the DEP of a planned facility modification to remove chlorine from the strainer backwash discharge and submitted an Emergency Authorization request to the DEP with respect to Unit 3 for this planned activity and ongoing discharge. Authorization to proceed with the modification was received from the DEP on October 1,1997 and an I!mergency Authorization covering both the modification and the strainer backwash discharge at Unit 3 was issued by the DEP on January 12,1998.
On June 3, the pil at DSN 006 was found to be as high as 9.58 (permit limit 9.0) for a limited time. It was believed that the high pil was due to wastewater containing alkaline concrete grout that had inadvertently entered the Unit 2 East Condenser Pit sump.
l In June, the intake measurements taken at Unit 1 intake were used in determining the differential temperature across each unit and in calculating heat loading.
I Measurement at Unit 3 could not take place because the circulating water pumps were not in operation and there was insufficient flow within the intake piping to l
allow the temperature probe to obtain readings. This does not appear to represent l
a permit exception or exceedance.
l In July, NNECO submitted an application for NPDES pennit renewal to the DEP.
As required by the EPP, copies of this application, and of subsequent correspo dence providing further information, were sent concurrently to the NRC.
In July, notification was made to the DEP that, during a maintenance tetivity l
l involving de-silting of the Unit 3 intake structure, drainage from a dampster l
intended to retain silt pumped from the bottom of the Unit 3 intake bays flowed into drains leading to DSN 006. The activity was suspended and a Temporary l
Authorization for this activity was subsequently obtained from the DEP.
In July, NNECO submitted revised Discharge Monitoring Reports relating primarily to the inclusion of additional sampling data for certain discharge locations. Revisions included the period from January through April 1997. As a result, certain DMRs for DSNs 001C-3,001C-6 and 001C-6(b) were revised.
In July, it was determined that the daily composite sampling protocol used for DSN 006 may have resulted in time intervals between certain samples to be in excess of the required 60 minutes. Sampling protocols were upgraded to prevent recurrence.
1997 AEPPOR 5